If you've watched more than 30 minutes of NFL football this season, you've certainly seen the commercial with the Denver Broncos fan who misses his team's scoring plays every time he goes down to the basement to get more beer.

He figures he's responsible for Peyton Manning finding Demaryius Thomas, Wes Welker or any of their other offensive weapons, and that all he has to do to get another touchdown is go back into the basement.

He's cracked the code.

Jeff Bruhl wishes figuring out the Lake Pontchartrain Causeway were only that easy. The first hour or so of every trip to the combined 48 miles of bridge stanchions is nothing but an investigation. Bruhl is Sherlock Holmes searching for clues.

The first couple hundred casts are usually about as productive as a beach bum when the surf's up. Those casts add very little meat to the box, but each one gives subtle hints about putting together that day's speckled-trout puzzle. There's never a picture on the box that shows where each piece goes.

"Every day is a new day out here," Bruhl said.

But on mild December days, the Causeway's code is always worth cracking. In the spring, the parallel bridges are as likely to hold hundreds of thousands of 12-inch speckled trout as they are croakers, redfish, black drum and freshwater catfish.

When winter starts approaching, however, the trash leaves, and the bridge itself seems supported on the backs of line-stripping speckled trout. These piscatorial Atlases are as long as a man's arm, and they fight like angry redfish, sizzling drags and refusing to come to the surface until forced.

An hour invested each trip figuring out the place is time well spent for Bruhl.

It certainly was on Tuesday morning. With southerly winds in the forecast, Bruhl deviated from his normal course of action by launching on the south shore at the Bonnabel boat launch and running 8 miles up to what north-shore anglers call the "16 mile."

The weather was as dreary as the previous night's Saints game, with fog coalescing into pouring rain that would fall for a while before turning back into a heavy mist. Bruhl was soaked to the bone, but on the positive side of the ledger, there was no wind to impede his fishing progress and his hunt for clues.

He weaved back and forth, hitting the outside of the north-bound span for a while before moving between the bridges, casting to each side, and then crossing to the outside of the south-bound span.

He picked up three or four fish before working his way into a long lull. The fish he caught were all random, showing no evidence of any distinct pattern, so Bruhl decided to run just a few more miles north to the "12 mile," one of his favorite stretches of the bridge.

"If you look on a map, this area is straight out from (Pass Manchac)," Bruhl said. "You'll usually have current here when you won't have it anywhere else."

Sure enough, the water was falling, wrapping around the pilings as it headed toward the Rigolets far to the east.

Bruhl also made a slight change of techniques. He had been fishing a 3/8-ounce jighead with an assortment of soft-plastics, and had been hopping the lure. But with the water temperature in the mid-50s, he figured the fish were probably a little sluggish. So he tied on a 1/2-ounce jighead instead.

That allowed him to slow-roll the bait along the bottom rather than hopping it.

"This time of year, when the water's cool like this, a lot of times I like to use my reel to move the bait rather than my rod," he said.

Bruhl wasn't sure if the alteration would matter, but no Causeway angler will ever crack the code if he doesn't change things up. And Bruhl is used to that. A resident of Covington, he's been fishing the Causeway since he was a boy, and has seen just about every technique an angler can think of work on the bridge.

Many entirely buck protocol. For instance, conventional wisdom is to fish the downcurrent sides of the pilings, but Bruhl threw that out the window when he hit the 12-mile. He started between the bridges, fishing the north-bound span, and it was there he cracked the code.

The fish were holding between the first and second stanchions, and they seemed to absolutely adore Bruhl's slow, steady retrieve along the bottom. On nearly every other cast between the first and second stanchion, Bruhl caught a speckled trout.

If he cast anywhere else on any other stanchion, he wouldn't get a bite. The consistency of where the fish were holding was a remarkable thing to see.

None were the pigs the Causeway is capable of producing this time of year, but every fish would be considered a giant in virtually any other destination. At one point Bruhl landed a fish that looked like a throwback compared to the others. He laid it on a ruler, and it measured 18 inches.

That's when you know you're on big fish.

"Over the years, I've seen 8- and 9-pounders come off the Causeway, but any day you come, you've got the realistic potential to catch a 6- or 7-pounder," Bruhl said. "You may not catch a limit, but most days this time of year, you can catch a dozen to two dozen 3- to 5-pounders out here."

The Causeway bite really got rolling nearly a month ago when South Louisiana got its first significant cold front. Word spread quickly among anglers, and fishing pressure on the bridge increased substantially.

The great thing about the Causeway, though, is that its location in the middle of one of Louisiana's largest waterbodies limits the exposure of the fish to consistent pressure. Windy days make the surface too rough to comfortably fish, and persistent winds turn the lake into a mud hole.

Those anglers who can pick their days, however, would be crazy to fish anywhere else over the next month when conditions in the lake are right. According to Bruhl, the bite is just getting started.

"Usually Thanksgiving to Christmas is the best time to come out here to catch big fish," he said. "It's water temperature related, but it also has to do with the migration of the shrimp. This year, we had a lot of fresh water in the lake, and it seemed like everything was delayed. It's on now, though."

There are no magic spots for fishing the Causeway. The fish could be anywhere on any given day. Anglers with less experience on the bridge often wrongly assume making a move is pointless since the structure is virtually identical from one side of the lake to the other.

But Bruhl and other Causeway veterans will fish a hundred-yard stretch before picking up and moving a couple of miles and doing the same thing. If they get a few fish, they'll work that same stretch over and over until the action there shuts down. Then they'll move again.

For whatever reason, there are always stretches that are hotter than others.

Another essential key is getting the lure to the bottom. Bruhl does that by fishing 3/8- or 1/2-ounce jigheads on 10-pound-test fluorocarbon. The line's incredibly light considering he's targeting big trout around structure they can wrap around during the fight, but the thin line produces less friction with the water, allowing the lure to hold bottom more easily. He may lose more fish, but he feels he gets a lot more bites with the lighter line.

The bite along the Causeway is mostly very subtle. Anglers waiting to feel a sharp jolt charge up their line will miss most of their bites.

"Most of the time, you're just going to feel something heavy or mushy on the end," Bruhl said. "Very seldom do you feel a tap. Usually that's small fish or croakers that are tapping it."

When Bruhl feels anything that could even remotely be a fish, he sets the hook. Lots of times, it's a waste of effort, but it's worth it when a little bit of heaviness on the line turns out to be a 4-pound trout.

He also pays close attention to what his line's doing. He studies it to see what the wind and current are making it do on each cast, and when it doesn't act as it should, he sets the hook.

"It's a lot like Texas-rig worm fishing for bass," he said. "You've got to watch your line. It might jump or move to the side against the current. You know something's taking it."

Causeway speckled trout are notorious for hitting a lure and spitting it before an angler can even have an internal mind debate about setting the hook, so to speed up that process, Bruhl fishes with his rod at the 3 o'clock position. From there, he can quickly jerk the rod skyward to bury the hook in a big trout's lip.

But whether he hits a fish or misses one, Bruhl will pay close attention to how and where that fish was holding.

"You've got to figure out on any given day where the fish are relating to the pilings that day," he said. "Sometimes it's due to the wind; sometimes it's due to the sun; sometimes it's just tidal flow.

"There might be an outgoing tide, and they're all on the front side. Some days, you'll have a wind with the tide moving opposite underneath, and they'll be in an entirely different position."

Still, even when Bruhl figures that out, he'll make no more than two casts to any particular stanchion.

"Just go to the next piling," he advised. "When they're out here, you'll get a bite on every cast but on a different piling. That's the biggest mistake I see guys make out here. They'll catch one, and they think there's a school there, but there's not. It's usually just two or three fish on a piling. You'll pick one up, and just move on to the next one."

Bait color is also more important on the Causeway than at other areas, Bruhl said. The lake can sometimes get too pretty, and then subtle colors like shrimp creole and blue moon work best. During Tuesday's trip, the water at mid-lake was green with just the slightest of stains to it. Visibility was about 2 1/2 feet.

Bruhl tried several colors, but the fish showed a distinct preference for avocado Bayou Chubs with their tails dyed chartreuse with a dunk in Dip-N-Glo.

Air temperatures this week have been warm, and the temperature of the lake is climbing every day. There's another front in the forecast for this weekend, however, and that will begin to drop water temperature again. Anglers looking to make a foray into the lake to fish the Causeway would be wise to monitor how much the temperature drops and plan their trips accordingly.

When the water temperature gets down around 50 degrees, the specks won't bite at all. On Tuesday's trip, Bruhl found the water to range between 54 and 56 degrees. Optimal water temperature is 60 to 62, he said.

Bruhl will be watching the lake temperature like a hawk, and when it gets right again, he'll be back at the Causeway trying to once again crack the code.